maxMap

Calculates the maximum from value array according to the keys specified in the key array.

Syntax

maxMap(key, value)

or

maxMap(Tuple(key, value))

Alias: maxMappedArrays

Note

• Passing a tuple of keys and value arrays is identical to passing two arrays of keys and values.
• The number of elements in key and value must be the same for each row that is totaled.

Parameters

• key — Array of keys. Array.
• value — Array of values. Array.

Returned value

• Returns a tuple of two arrays: keys in sorted order, and values calculated for the corresponding keys. Tuple(Array, Array).

Example

Query:

SELECT maxMap(a, b)
FROM VALUES('a Array(Char), b Array(Int64)', (['x', 'y'], [2, 2]), (['y', 'z'], [3, 1]))

Result:

┌─maxMap(a, b)───────────┐
│ [['x','y','z'],[2,3,1]]│
└────────────────────────┘

maxMappedArrays

Introduced in: v20.5

Calculates the maximum from value array according to the keys specified in the key array.

Note

• Passing a tuple of keys and value arrays is identical to passing an array of keys and an array of values.
• The number of elements in key and value must be the same for each row that is totaled.

Syntax

maxMappedArrays(key, value)
maxMappedArrays(Tuple(key, value))

Arguments

• key — Array of keys. Array(T)
• value — Array of values. Array(T)

Returned value

Returns a tuple of two arrays: keys in sorted order, and values calculated for the corresponding keys. Tuple(Array(T), Array(T))

Examples

Usage example

SELECT maxMappedArrays(a, b)
FROM VALUES('a Array(Char), b Array(Int64)', (['x', 'y'], [2, 2]), (['y', 'z'], [3, 1]));

┌─maxMappedArrays(a, b)────────────────┐
│ [['x', 'y', 'z'], [2, 3, 1]].        │
└──────────────────────────────────────┘